Patterning method of high-molecular polymer film

Abstract

The invention provides a patterning method of a high-molecular polymer film. The patterning method comprises the following steps: forming a hard mask material layer with a preset thickness h0 on a high-molecular polymer film layer; forming a photoresist layer with a preset shape on the hard mask material layer, wherein the photoresist layer is provided with a covering area and an exposed area; the hard mask material layer in the exposed area is etched, the first preset depth h1 is etched, and the first preset depth h1 is smaller than the preset thickness h0; removing the photoresist layer; carrying out whole-surface etching on the hard mask material layer, and etching a second preset depth h2; the exposed high-molecular polymer thin film layer is etched; removing the hard mask material layer to form a high-molecular polymer film layer with a preset shape; wherein the second preset depth h2, the first preset depth h1 and the preset thickness h0 meet the condition that h2 = h0-h1. The problem that in the prior art, the imaging quality of a high-molecular polymer film is poor is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-nano processing equipment, and more particularly, to a method for patterning a polymer thin film. Background Art

[0002] Polymer thin films have a wide range of applications in the fields of optoelectronic devices, biomedical devices, etc. Among them, polymer waveguide devices are an important type of optoelectronic device, which have the advantages of low loss, low cost, and easy integration. Polymer waveguide devices usually consist of a sandwich structure of a cladding layer + a polymer layer + a cladding layer. The materials of the cladding layer and the polymer layer can be PDMS (Polydimethylsiloxane), PMMA (Polymethylmethacrylate), etc. Among them, the polymer layer serves as the core layer and needs to undergo a patterning process to form the required waveguide structure.

[0003] Currently, there are mainly two patterning processes for polymer waveguide devices: one is to use a photoresist as an etching mask, and the other is to use a hard mask as an etching mask. The process flow of using a photoresist as an etching mask is relatively simple, but due to the low etching selectivity and poor resolution of the photoresist itself, it is difficult to meet the requirements of polymer waveguide devices for the minimum feature size and edge accuracy. The process flow of using a hard mask as an etching mask is relatively complex, but it can improve the etching selectivity and resolution, and prepare a finer and smoother waveguide structure.

[0004] Currently, there are two common methods for preparing hard masks: the lift-off method and the etching method. In the lift-off method, a conventional organic lift-off solution is usually used to remove the hard mask material layer, and the polymer layer (such as PMMA) is easily soluble in the conventional organic lift-off solution. When removing the hard mask material layer, the polymer layer is likely to dissolve in the lift-off solution, resulting in damage to the polymer layer.

[0005] The etching method refers to preparing a hard mask material layer (such as a metal coating or an oxide thin film layer) on the entire surface of a polymer thin film, then patterning the hard mask material layer using a photoresist, and using a dry etching device (such as IBE (Ion Beam Etching), RIE (Reactive Ion Etching), or ICP (Inductive Coupled Plasma Emission Spectrometer), etc.) to etch it to obtain a hard mask. Then, using this hard mask as a mask, the polymer layer is etched, and finally the hard mask is removed. The disadvantage of this method is that when the hard mask is patterned, the photoresist needs to be removed. If the photoresist is removed by wet method, the same conventional photoresist removers (such as acetone, ethanol, and NMP (N-Methylpyrrolidone), etc.) will also damage the polymer layer. If the photoresist is removed by dry method, since the polymer (such as PMMA) itself can be used as a photoresist, when the photoresist on the hard mask is removed by dry method, the exposed polymer layer will be removed or damaged on the surface along with the photoresist.

[0006] In summary, the existing patterning methods for polymer thin films using hard masks as etching masks all have certain defects and deficiencies, and it is difficult to ensure the patterning quality of the polymer core layer. Therefore, there is an urgent need to provide a new patterning method for polymer thin films using hard masks as etching masks to solve the above problems. Summary of the Invention

[0007] The main object of the present invention is to provide a patterning method for polymer thin films to solve the problem of poor patterning quality of polymer thin films in the prior art.

[0008] To achieve the above object, according to one aspect of the present invention, there is provided a patterning method for polymer thin films, including: forming a hard mask material layer with a preset thickness h0 on the polymer thin film layer; forming a photoresist layer with a preset shape on the hard mask material layer, the photoresist layer having a covered area and an exposed area; etching the hard mask material layer in the exposed area and etching to a first preset depth h1, the first preset depth h1 being less than the preset thickness h0; removing the photoresist layer; etching the hard mask material layer over the entire surface and etching to a second preset depth h2; etching the exposed polymer thin film layer; removing the hard mask material layer to form a polymer thin film layer with a preset shape; where the second preset depth h2, the first preset depth h1, and the preset thickness h0 satisfy h2 = h0 - h1.

[0009] Further, before the process of forming the hard mask material layer with a preset thickness h0 on the polymer thin film layer, the following steps are also included: forming a first coating layer on the substrate layer; forming a polymer thin film layer on the first coating layer.

[0010] Further, during the process of forming the first coating layer on the substrate layer, the first coating layer is formed by means of coating.

[0011] Further, during the process of forming the polymer thin film layer on the first coating layer, the polymer thin film layer is formed by means of coating.

[0012] Further, after the process of removing the hard mask material layer to form a polymer thin film layer with a preset shape, the following step is also included: forming a second coating layer on the polymer thin film layer.

[0013] Further, the materials of the first coating layer, the second coating layer and the polymer thin film layer include at least one of acrylic resin, polydimethylsiloxane, and polyimide.

[0014] Further, during the process of forming the second coating layer on the polymer thin film layer, the second coating layer is formed by means of coating.

[0015] Further, during the process of forming the hard mask material layer with a preset thickness h0 on the polymer thin film layer, the hard mask material layer is formed by means of magnetron sputtering or thermal evaporation.

[0016] Further, the number of etching times of the hard mask material layer is greater than or equal to two.

[0017] Further, during the process of etching the hard mask material layer in the exposed area and etching to a first preset depth h1, where the first preset depth h1 is less than the preset thickness h0, the hard mask material layer in the exposed area is etched at least once. When the hard mask material layer in the exposed area is etched multiple times, the first preset depth h1 is accumulated through multiple etching times; and / or during the process of etching the hard mask material layer over the entire surface and etching to a second preset depth h2, the hard mask material layer over the entire surface is etched at least once. When the hard mask material layer over the entire surface is etched multiple times, the second preset depth h2 is accumulated through multiple etching times.

[0018] Further, the hard mask material layer includes at least one of a metal coating layer and an oxide thin film layer.

[0019] Applying the technical solution of the present invention, the method for patterning a polymer thin film includes: forming a hard mask material layer with a preset thickness h0 on the polymer thin film layer; forming a photoresist layer with a preset shape on the hard mask material layer, the photoresist layer having a covered area and an exposed area; etching the hard mask material layer in the exposed area and etching to a first preset depth h1, the first preset depth h1 being less than the preset thickness h0; removing the photoresist layer; etching the entire surface of the hard mask material layer and etching to a second preset depth h2; etching the exposed polymer thin film layer; removing the hard mask material layer to form a polymer thin film layer with a preset shape; wherein, the second preset depth h2, the first preset depth h1 and the preset thickness h0 satisfy h2 = h0 - h1.

[0020] By forming a photoresist layer with a preset shape on the hard mask material layer, a part of the hard mask material layer is covered by the photoresist layer, while another part of the hard mask material layer is exposed to the outside, so as to facilitate the subsequent etching of the hard mask material layer in the exposed area. When etching the hard mask material layer in the exposed area, the etching depth of the hard mask material layer is less than the thickness of the hard mask material layer, so as to leave part of the hard mask material to protect the polymer thin film layer. Since part of the hard mask material remains in the exposed area, when removing the photoresist layer, it will not damage the polymer thin film layer, which is beneficial to the integrity of the polymer thin film layer. Since there is a height difference between the hard mask material layer in the exposed area and the hard mask material layer in the covered area, the hard mask material layer in the exposed area can also be accurately removed to form a mask plate with a preset shape after removing the photoresist layer, and then the polymer thin film layer is etched. Since no damage is caused to the polymer thin film layer before etching the polymer thin film layer, the quality of patterning the polymer thin film layer is effectively improved, which is beneficial to preparing a finer and smoother waveguide structure and meets the requirements of the polymer waveguide device for the minimum feature size and edge accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The specification drawings forming a part of the present application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0022] Figure 1 It shows a schematic flow chart of the method for patterning a polymer thin film of an optional embodiment of the present invention.

[0023] Wherein, the above-mentioned drawings include the following reference numerals:

[0024] 10. Polymer thin film layer; 20. Hard mask material layer; 30. Photoresist layer; 40. Covered area; 50. Exposed area; 60. Substrate layer; 70. First coating layer. Detailed implementation manners

[0025] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0026] It should be pointed out that, unless otherwise specified, all technical and scientific terms used in the present application have the same meanings as those commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0027] In the present invention, unless otherwise stated, the orientation terms such as "upper, lower, top, bottom" are usually in the directions shown in the drawings, or in the vertical, perpendicular or gravitational directions of the components themselves; similarly, for the convenience of understanding and description, "inner, outer" refer to the inner and outer of the contours of the components themselves, but the above orientation terms do not limit the present invention.

[0028] In order to solve the problem of poor patterning quality of polymer thin films in the prior art, the present invention provides a patterning method for polymer thin films.

[0029] As Figure 1 shown, the patterning method for polymer thin films includes: forming a hard mask material layer 20 with a preset thickness h0 on the polymer thin film layer 10; forming a photoresist layer 30 with a preset shape on the hard mask material layer 20, and the photoresist layer 30 has a covered area 40 and an exposed area 50; etching the hard mask material layer 20 in the exposed area 50 and etching to a first preset depth h1, and the first preset depth h1 is less than the preset thickness h0; removing the photoresist layer 30; performing a full-surface etching on the hard mask material layer 20 and etching to a second preset depth h2; etching the exposed polymer thin film layer 10; removing the hard mask material layer 20 to form a polymer thin film layer 10 with a preset shape; wherein, the second preset depth h2, the first preset depth h1 and the preset thickness h0 satisfy h2 = h0 - h1.

[0030] By forming a photoresist layer 30 with a preset shape on the hard mask material layer 20, a part of the hard mask material layer 20 is covered by the photoresist layer 30, while another part of the hard mask material layer 20 is exposed to the outside, so as to facilitate the subsequent etching of the hard mask material layer 20 in the exposed area 50. When etching the hard mask material layer 20 located in the exposed area 50, the etching depth of the hard mask material layer 20 is less than the thickness of the hard mask material layer 20, so as to leave part of the hard mask material to protect the polymer thin film layer 10. Since part of the hard mask material remains in the exposed area 50, the polymer thin film layer 10 will not be damaged when the photoresist layer 30 is removed, which is beneficial to the integrity of the polymer thin film layer 10. Since there is a height difference between the hard mask material layer 20 located in the exposed area 50 and the hard mask material layer 20 located in the covered area 40, the hard mask material layer 20 located in the exposed area 50 can be accurately removed after the photoresist layer 30 is removed to form a mask plate with a preset shape, and then the polymer thin film layer 10 is etched. Since no damage is caused to the polymer thin film layer 10 before etching the polymer thin film layer 10, the quality of patterning of the polymer thin film layer 10 is effectively improved, which is beneficial to preparing a finer and smoother waveguide structure and meets the requirements of the polymer waveguide device for the minimum feature size and edge accuracy.

[0031] Since the material of the photoresist layer 30 is softer than that of the hard mask material layer 20 and is easier to remove than the hard mask material layer 20, the influence on the hard mask material layer 20 is smaller when removing the photoresist layer 30, making the accuracy of the hard mask material layer 20 higher during imaging, and thus improving the quality of patterning of the polymer thin film layer 10.

[0032] In the prior art, the etching time of the hard mask material layer 20 is relatively long, which increases the time of the photoresist layer 30 in the etching equipment, resulting in carbonization or deformation of the photoresist layer 30. The carbonized or denatured photoresist layer 30 is extremely difficult to remove whether by wet method or dry method. In this application, the step of removing the photoresist layer 30 is after the first etching of the hard mask material layer 20 to an etching depth of the first preset depth h1. The time of the photoresist layer 30 in the etching equipment is shortened, and the risk of carbonization or deformation of the photoresist layer 30 is reduced, so that the time for removing the photoresist layer 30 is shortened. It should be noted that during the process of etching the exposed polymer thin film layer 10, a dry etching equipment can be used.

[0033] In the process of removing the hard mask material layer 20 to form a polymer thin film layer 10 with a preset shape, a dry etching equipment can be used to remove the remaining hard mask material layer 20.

[0034] Specifically, before the process of forming the hard mask material layer 20 with a preset thickness h0 on the polymer thin film layer 10, it further includes: forming a first coating layer 70 on the substrate layer 60; forming the polymer thin film layer 10 on the first coating layer 70. The first coating layer 70 has a protective effect on the polymer thin film layer 10 to reduce stretching and damage to the polymer thin film layer 10.

[0035] It should be noted that the first coating layer 70 and the polymer thin film layer 10 can be an integrally formed structure, specifically, the first coating layer 70 and the polymer thin film layer 10 can be formed simultaneously on the substrate layer 60.

[0036] Optionally, during the process of forming the first coating layer 70 on the substrate layer 60, the first coating layer 70 is formed by a coating method. Using the coating method is beneficial to forming a uniform first coating layer 70.

[0037] Optionally, the first coating layer 70 can be coated by spin coating, roll coating, etc. Of course, other methods can also be selected to form the first coating layer 70, and no specific limitation is made here.

[0038] Specifically, during the process of forming the polymer thin film layer 10 on the first coating layer 70, the polymer thin film layer 10 is formed by a coating method. Using the coating method is beneficial to forming a uniform polymer thin film layer 10.

[0039] Optionally, the polymer thin film layer 10 can be coated by spin coating, roll coating, etc. Of course, other methods can also be selected to form the polymer thin film layer 10, and no specific limitation is made here.

[0040] Optionally, after the process of removing the hard mask material layer 20 by using a dry etching device to form a polymer thin film layer 10 with a preset shape, it further includes: forming a second coating layer on the polymer thin film layer 10. After forming the polymer thin film layer 10 with a preset shape, a second coating layer is formed on the polymer thin film layer 10, thereby forming a sandwich structure of coating layer + polymer thin film layer 10 + coating layer. The sandwich structure protects the polymer thin film layer 10 on both sides, further improving the protection effect on the polymer thin film layer 10.

[0041] Optionally, the materials of the first coating layer 70, the second coating layer, and the polymer thin film layer 10 include at least one of acrylic resin, polydimethylsiloxane, and polyimide. The materials of the first coating layer 70, the second coating layer, and the polymer thin film layer 10 can be selected according to the actual usage requirements of the polymer thin film. Of course, the materials of the first coating layer 70, the second coating layer, and the polymer thin film layer 10 can be the same or different, and no specific limitation is made here.

[0042] It should be noted that when the materials of the first coating layer 70 and the polymer thin film layer 10 are the same, the first coating layer 70 and the polymer thin film layer 10 can be prepared in the same process. Of course, the first coating layer 70 and the polymer thin film layer 10 can also be formed step by step, and no specific limitation is made here.

[0043] Optionally, the first coating layer 70 and the polymer thin film layer 10 can be an integral structure. When the first coating layer 70 and the polymer thin film layer 10 are an integral structure, the two can be collectively referred to as the polymer thin film layer 10. When patterning the polymer thin film layer 10 at this time, it is not necessary to etch all the exposed polymer thin film layer 10.

[0044] The material of the polymer thin film layer 10 in this application is not restricted by any conditions. Whether the polymer thin film layer 10 is soluble in organic or inorganic solvents, the method in this application can be used for patterning.

[0045] Specifically, during the process of forming the second coating layer on the polymer thin film layer 10, the second coating layer is formed by a coating method. Using the coating method is beneficial to forming a uniform second coating layer.

[0046] Optionally, the second coating layer can be coated by spin coating, roll coating, etc. Of course, other methods can also be selected to form the second coating layer, and no specific limitation is made here.

[0047] Optionally, during the process of forming the hard mask material layer 20 with a preset thickness h0 on the polymer thin film layer 10, the hard mask material layer 20 is formed by magnetron sputtering or thermal evaporation. During the process of forming the hard mask material layer 20, the process for preparing the hard mask material layer 20 can be selected according to the material of the hard mask material layer 20 and the material of the polymer thin film layer 10, and no specific limitation is made here.

[0048] In the patterning method of the polymer thin film in this application, the etching step can be carried out using a dry etching equipment or a wet etching equipment, which can be selected according to needs and will not be specifically limited here. Using dry etching is more conducive to process control, and the control of patterns with small feature sizes is more precise, which is more conducive to improving the pattern accuracy.

[0049] In the dry etching of this application, conventional gases such as argon and fluorine-based gases can be selected. Toxic gases such as chlorine-based gases do not need to be selected during the etching process, which is safer and more environmentally friendly.

[0050] In the process of this invention, no organic solvents other than the developer are used, and the polymer thin film layer 10 will not be damaged during the process.

[0051] When the etching step in the patterning method of the polymer thin film in this application uses a dry etching equipment, no conventional alkali is used, and no corresponding cationic metals will be introduced during the process, which is more conducive to process control. The patterning method of the polymer thin film in this application is not limited by the feature size. For the polymer thin film layer 10 with large and small feature sizes, the pattern accuracy can be guaranteed. In addition, such a setting makes it so that no organic solvents other than the developer are used in the patterning method of the polymer thin film in this application, and it will not cause damage to the polymer thin film layer 10 before etching.

[0052] When using a dry etching equipment for etching, at least one of the IBE equipment (Ion Beam Etching), RIE equipment (Reactive Ion Etching), and ICP equipment (Inductive Coupled Plasma Emission Spectrometer) can be used, and the dry etching equipment can be selected according to specific usage requirements.

[0053] This invention can utilize the high etching selectivity and high resolution of the IBE equipment and the RIE equipment to prepare a finer and smoother waveguide structure, meeting the requirements of the polymer waveguide device for the minimum feature size and edge accuracy. At the same time, the use of organic solvents or acid-base solutions to damage the polymer core layer is reduced, ensuring the integrity and patterning quality of the polymer thin film layer 10.

[0054] Of course, in some etching steps, a wet process can also be used, which will not be specifically limited here. Dry etching is preferably used. Dry etching is more conducive to process control compared to wet etching, and the control of patterns with small feature sizes is more precise.

[0055] Optionally, the number of etching times for the hard mask material layer 20 is greater than or equal to two. That is, the total number of etching times for the hard mask material layer 20 can be more than two times, which can be designed according to the pattern to be etched on the polymer thin film layer 10, and no specific limitation is made here. For example, the total number of etching times for the hard mask material layer 20 can be three etching times, four etching times, etc., and no specific limitation is made here.

[0056] Specifically, during the etching of the hard mask material layer 20 in the exposed area 50 to an etching depth of a first preset depth h1, where the first preset depth h1 is less than the preset thickness h0, the hard mask material layer 20 in the exposed area 50 is etched at least once. Among them, when the hard mask material layer 20 in the exposed area 50 is etched multiple times, the first preset depth h1 is accumulated through multiple etching times. That is to say, when etching to the first preset depth h1, it can be achieved through multiple etching times, and the accumulated etching depth through multiple times is h1.

[0057] Alternatively, during the overall etching of the hard mask material layer 20 to an etching depth of a second preset depth h2, the overall etching of the hard mask material layer 20 is performed at least once. Among them, when the overall etching of the hard mask material layer 20 is performed multiple times, the second preset depth h2 is accumulated through multiple etching times. That is to say, when etching to the second preset depth h2, it can be achieved through multiple etching times, and the accumulated etching depth through multiple times is h2.

[0058] Optionally, the hard mask material layer 20 includes at least one of a metal coating layer and an oxide thin film layer. It can be a single-layer metal coating layer, a multi-layer metal coating layer, a single-layer oxide thin film layer, a multi-layer oxide thin film layer, or a combined layer of a metal coating layer and an oxide thin film layer. For example, it can be a combined layer formed by alternating a metal coating layer and an oxide thin film layer.

[0059] The oxide thin film layer can be a metal oxide thin film layer or a non-metal oxide thin film layer, and no specific limitation is made here, as long as the structure of the hard mask material layer 20 has relatively high strength.

[0060] Optionally, the material of the hard mask material layer 20 can include at least one of aluminum, copper, gold, silver, platinum, titanium, chromium, nickel, tantalum, tungsten, titanium nitride, titanium-tungsten alloy, nickel-titanium alloy, tantalum nitride, aluminum oxide, silicon dioxide, silicon nitride, silicon oxynitride, and phosphorus-doped silicate glass.

[0061] Optionally, during the process of removing the photoresist layer 30, a dry film removal device is selected to remove the photoresist layer 30. Since the dry film removal device will not remove the hard mask material layer 20 when removing the photoresist layer 30, the graphic integrity of the hard mask material layer 20 is ensured, which is beneficial to higher precision and better quality of the patterning of the polymer thin film layer 10.

[0062] Of course, other devices can also be selected to remove the photoresist layer 30 when removing the photoresist layer 30. For example, IBE equipment, RIE equipment, ICP equipment, etc. can be used. There is no specific limitation here, as long as it is ensured that the polymer thin film layer 10 will not be damaged when removing the photoresist layer 30.

[0063] Specifically, during the process of forming a photoresist layer 30 with a preset shape on the hard mask material layer 20, a photoresist material is coated on the hard mask material layer 20 to form a glue layer; a projection type lithography machine is used to project a preset shape onto the glue layer and expose the glue layer; a developer is used to develop the glue layer to form a photoresist layer 30 with a preset shape; among them, the area washed away by the developer is the exposed area 50, and the area not washed away by the developer is the covered area 40. The photoresist material used in this application can be any commercially available photoresist that meets the resolution requirements, which reduces the limitation on the photoresist material and is beneficial to cost reduction.

[0064] The process flow of the present invention is simple, reliable, and easy to control, suitable for mass production of polymer waveguide devices, reducing production costs and improving production efficiency.

[0065] Example 1

[0066] Step 1: Spin-coat 10 um thick PDMS (polydimethylsiloxane) on the substrate to form a first coating layer 70;

[0067] Step 2: Spin-coat 1 um thick PMMA (polymethyl methacrylate) on the first coating layer 70 to form a polymer thin film layer 10;

[0068] Step 3: Select magnetron sputtering to grow a 10 nm Cr layer and a 120 nm Au layer to form a hard mask material layer 20;

[0069] Step 4: Spin-coat 800 nm AR80 photoresist to form a glue layer, use a projection type lithography machine to project a preset shape onto the glue layer to expose the glue layer, and use 3038 solution to develop the glue layer to form a photoresist layer 30 with a preset shape;

[0070] Step 5: Using the photoresist layer 30 as a mask, select IBE equipment to etch the hard mask material layer 20 in the exposed area 50, and the etching depth is 70 nm;

[0071] Step 6: Use an oxygen plasma device to remove the photoresist layer 30.

[0072] Step 7: Continue to etch the hard mask material layer 20 using IBE until the remaining 60 nm thick hard mask material layer 20 in the exposed area 50 is etched away, forming a hard mask material layer 20 with a preset shape.

[0073] Step 8: Using the hard mask material layer 20 with a preset shape as a mask, select an RIE device to etch the polymer thin film layer 10 to an etching depth of 1 um, forming a polymer thin film layer 10 with a preset shape.

[0074] Step 9: Spin-coat 10 um of PDMS on the polymer thin film layer 10 with a preset shape to form a second coating layer.

[0075] Example 2

[0076] The difference from Example 1 is that the equipment and some parameters used in the patterning method are different.

[0077] Step 1: Spin-coat 10 um thick PDMS (polydimethylsiloxane) on the substrate to form a first coating layer 70;

[0078] Step 2: Spin-coat 1 um thick PMMA (polymethyl methacrylate) on the first coating layer 70 to form a polymer thin film layer 10;

[0079] Step 3: Select magnetron sputtering to grow a 10 nm Cr layer and a 100 nm Au layer to form a hard mask material layer 20;

[0080] Step 4: Spin-coat 800 nm SPR955 photoresist to form a photoresist layer, use a projection lithography machine to project a preset shape onto the photoresist layer for exposure, and use a 3038 solution to develop the photoresist layer to form a photoresist layer 30 with a preset shape;

[0081] Step 5: Using the photoresist layer 30 as a mask, select an IBE device to etch the hard mask material layer 20 in the exposed area 50 to an etching depth of 60 nm;

[0082] Step 6: Use an oxygen plasma device to remove the photoresist layer 30.

[0083] Step 7: Continue to etch the hard mask material layer 20 using IBE until the remaining 50 nm thick hard mask material layer 20 in the exposed area 50 is etched away, forming a hard mask material layer 20 with a preset shape.

[0084] Step 8: Using the hard mask material layer 20 with a preset shape as a mask, select an ICP device to etch the polymer thin film layer 10 with an etching depth of 1 um to form a polymer thin film layer 10 with a preset shape.

[0085] Step 9: Spin-coat 10 um of PDMS on the polymer thin film layer 10 with a preset shape to form a second coating layer.

[0086] Example 3

[0087] The difference from Example 1 is that the equipment and some parameters used in the patterning method are different.

[0088] Step 1: Grow a 100-nm Al (aluminum) layer on the substrate to form a first coating layer 70.

[0089] Step 2: Spin-coat 1 um thick PMMA (polymethyl methacrylate) on the first coating layer 70 to form a polymer thin film layer 10.

[0090] Step 3: Select magnetron sputtering to grow a 10-nm Cr layer and a 100-nm Au layer to form a hard mask material layer 20.

[0091] Step 4: Spin-coat 800-nm SPR955 photoresist to form a photoresist layer, use a projection lithography machine to project a preset shape onto the photoresist layer to expose the photoresist layer, and use a 3038 solution to develop the photoresist layer to form a photoresist layer 30 with a preset shape.

[0092] Step 5: Using the photoresist layer 30 as a mask, select an IBE device to etch the hard mask material layer 20 in the exposed area 50 with an etching depth of 60 nm.

[0093] Step 6: Use an oxygen plasma device to remove the photoresist layer 30.

[0094] Step 7: Use IBE to continue etching the hard mask material layer 20 until the remaining 50-nm thick hard mask material layer 20 in the exposed area 50 is etched completely to form a hard mask material layer 20 with a preset shape.

[0095] Step 8: Using the hard mask material layer 20 with a preset shape as a mask, select an ICP device to etch the polymer thin film layer 10 with an etching depth of 1 um to form a polymer thin film layer 10 with a preset shape.

[0096] Step 9: Spin-coat 10 um of PDMS on the polymer thin film layer 10 with a preset shape to form a second coating layer.

[0097] Obviously, the embodiments described above are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0098] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0099] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order different from those illustrated or described herein.

[0100] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for patterning a polymer film, characterized in that, comprising: forming a hard mask material layer (20) with a preset thickness h0 on the polymer film layer (10); forming a photoresist layer (30) with a preset shape on the hard mask material layer (20), the photoresist layer (30) having a covered area (40) and an exposed area (50); etching the hard mask material layer (20) within the exposed area (50) and etching to a first preset depth h1, the first preset depth h1 being less than the preset thickness h0; removing the photoresist layer (30); performing a full-surface etching on the hard mask material layer (20) and etching to a second preset depth h2; etching the exposed polymer film layer (10); removing the hard mask material layer (20) to form a polymer film layer (10) with the preset shape; wherein, the relationship among the second preset depth h2, the first preset depth h1 and the preset thickness h0 satisfies h2 = h0 - h1.

2. The method for patterning a polymer film according to claim 1, characterized in that, before the process of forming the hard mask material layer (20) with a preset thickness h0 on the polymer film layer (10), further comprising: forming a first coating layer (70) on a substrate layer (60); forming the polymer film layer (10) on the first coating layer (70).

3. The method for patterning a polymer film according to claim 2, characterized in that, during the process of forming the first coating layer (70) on the substrate layer (60), the first coating layer (70) is formed by a coating method.

4. The method for patterning a polymer film according to claim 2, characterized in that, during the process of forming the polymer film layer (10) on the first coating layer (70), the polymer film layer (10) is formed by a coating method.

5. The method for patterning a polymer film according to claim 2, characterized in that, after the process of removing the hard mask material layer (20) to form a polymer film layer (10) with the preset shape, further comprising: forming a second coating layer on the polymer film layer (10).

6. The method for patterning a polymer film according to claim 5, characterized in that, the materials of the first coating layer (70), the second coating layer, and the polymer film layer (10) include at least one of acrylic resin, polydimethylsiloxane, and polyimide.

7. The method for patterning a polymer film according to claim 5, characterized in that, during the process of forming the second coating layer on the polymer film layer (10), the second coating layer is formed by a coating method.

8. The method for patterning a polymer film according to any one of claims 1 to 7, characterized in that, In the process of forming the hard mask material layer (20) with a preset thickness h0 on the polymer film layer (10), the hard mask material layer (20) is formed by magnetron sputtering or thermal evaporation.

9. The patterning method of the polymer film according to any one of claims 1 to 7, wherein, the number of etching times of the hard mask material layer (20) is greater than or equal to two.

10. The patterning method of the polymer film according to any one of claims 1 to 7, wherein, in the process of etching the hard mask material layer (20) in the exposed area (50) and etching to a first preset depth h1, where the first preset depth h1 is less than the preset thickness h0, the hard mask material layer (20) in the exposed area (50) is etched at least once. When the hard mask material layer (20) in the exposed area (50) is etched multiple times, the first preset depth h1 is accumulated by multiple etchings; and / or in the process of etching the entire surface of the hard mask material layer (20) and etching to a second preset depth h2, the entire surface of the hard mask material layer (20) is etched at least once. When the entire surface of the hard mask material layer (20) is etched multiple times, the second preset depth h2 is accumulated by multiple etchings.

11. The patterning method of the polymer film according to any one of claims 1 to 7, wherein, the hard mask material layer (20) includes at least one of a metal coating layer and an oxide thin film layer.

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